Peripentadenia mearsii

Peripentadenia is a monotypic genus of the family Elaeocarpaceae represented by Peripentadenia mearsii (C. T. White) L. S. Smith, a tree growing in rain forests of northern Queensland. Besides unidentified minor alkaloids, the species yields one major alkaloid, peripentadenine (49) (87). Its molecular formula, C22H34N203, was established by high-resolution mass spectroscopy the presence of phenol, ketone, secondary amide, and tertiary amine functionalities was deduced from examination of spectroscopic data. 

Peripentadenia mearsii (C. White) L.S. Smith Sloanea woollsii F. Muell. 

Mearsine (336) was isolated as a minor alkaloid of Peripentadenia mearsii [703]. Its structure was determined with elemental analysis of the crystalline picrate, MS, IR, UV, and 13C NMR, diacetylation of the NaBH4 reduction product, and X-ray crystallography [703,704]. The structure was confirmed by synthesis of (+)-336 from (-)-5-methyl-2-cyclohexenone via a Mannich reaction [705]. The structure of 336 suggested its biosynthesis was from acetate via a polyketide pathway [703]. 

Three tropane alkaloids, two of which are new, have been isolated from the leaves of a tree belonging to the Queensland species Peripentadenia mearsii (C. T. White) L. S. Smith, (fam. Euphorbiaceae). The two new alkaloids are ( + )-(3R,6/ )-3a-acetoxy-6)S-hydroxytropane (1) and ( + )-2a-benzoyloxy-3/3-hydroxynortropane (2) (relative configuration only is shown here) the known alkaloid is 3 -benzoyloxytropane (3). 

The hydrolytic cleavage of Peripentadenine gave the 2-hydroxy-6-methylaceto-phenone. The Peripentadenine was obtained from dried milled bark of Peripentadenia mearsii (Elaeocarpaceae), collected at Boonjie (North Queensland) [2653],... 

Figure 22 Alkaloids of Elaeocarpus fuscoides, °° Peripentadenia mearsii and Elaeocar-pus sphaericu ° isoelaeocarpicine (860) isoelaeocarpine (861) elaeocarpine (862) elaeocarpenine (863) mearsamine (864) 3-oxoisoelaeocarpine (865) elaeocarpine A/-oxide (866).

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